Traditionally, the quantitative analysis of DFXM data and the theoretical description[1]}, [2]} of the method has relied on strong approximations. Most important is the kinematical approximation, which is to omit multiple-scattering effects, and which holds for small and for highly deformed crystals. Another approximation, which is build into the geometric-optics treatment of Bragg-scattering, is that infinitesimal sub-volumes in the sample scatter according to the Bragg-law for a perfect infinite crystal, and that the intensities scattered from such sub-volumes add together incoherently. In some cases (eg. for near-perfects crystallites and small defect-structures), however, such approximations cannot be afforded.
